More parametric CNC-cut tables for LowRider v3 (full sheet+): 3.625", 6", and 8" tall versions.
These are Fusion 360 archive files. Since I don’t have the paid version of F360, I cannot do the “live share” option. You can open these in Fusion 360, tweak as desired, and right click on the sketches that have “for DXF” in the name to export your DXFs for laying out and cutting.
Compared to my original table work here, these “version 2” tables have some parameter tweaks intended to make the tables more robust for scaling as needed and to make it easier to edit the number of X ribs and number of Y spars just by editing the parameters with those names.
Same height as the original table linked above. This table height is the lightest weight of the three, and it has the advantage of its torsion box being cut from a single full sheet of either 3/4" MDF or plywood.
While it can be quite strong, this thinness and lightness also means it’s the most susceptible to having material weight to cause it to bow ever so slightly.
For that reason it would probably serve best either on top of a cabinet type structure that supports shimming as needed, or by having 6 legs instead of 4, with 2 in the middle.
I got the “part 2” video edited & posted. Watch both part 1 (short) and part 2 (full length) to get the scoop on this awesome enhancement of my LowRider v3 CNC capabilities:
For LowRider v3 CNC, full sheet capable table, Part 1, prep & cross lap test
For LowRider v3 CNC, full sheet capable table, Part 2, CNC cut & assembly!
I’m a little salty that I built my table two weeks before these came together, so I haven’t really been following much, but are there multiple threads now with pre-designed tables?
I’ve noticed on thingiverse and printables, sometimes people will make a parametric fitting or bracket, ezport a collection that suits their project, then hoar the collection AND the parameteic model. Are you thinking of doing something like this for the table? It would be really cool for new builders to have a library, as this is really a hard thing to wrap a mind around.
Of course strength in torsion boxes come from at least these attributes (and perhaps more):
The skins. Extraordinary difference between one skin and both.
Increased height (tallness) of the box. The more the better. (But costs more.)
Increased number of spars and ribs. The more the better. (But costs more.)
Thickness of materials (more for spars and ribs, than for skins)
I’m no engineer, so I would not know until someone actually tests it out. Engineers have my admiration. They can use math to know in advance. I’m not there. LOL
UPDATE: The original post (link below) has newer versions and should be referenced/used instead of this thread. This thread is to be closed. Thank you!
Thanks for sharing your designs! I just finished my low rider and started cutting this table. Problem is, I don’t have access to a truck often so when I did I stocked up on MDF for this project. It seems I accidentally grabbed .63 inch MDF instead of .75. I won’t be able to get thicker sheets anytime soon. I just noticed this after my first cut lol.
Will I be able to use this slightly thinner MDF without jeopardizing the integrity of the table?
So the cross-lap joints depend on a tight fit to help the table be nice and solid and rigid. It’s not a show stopper as you could either edit the thickness parameter in the Fusion 360 file and re-save the DXF files used for your cut job, or you could perhaps use something for shims to tighten up the joints!
It would also depend on the quality and plys of your sheets. You’ll be paying dearly for 7-9 ply sheets but they would be by far the most stable. Look into millwright grade sheets which are amazingly strong. Check at Freeman Manufacturing, they have closeouts all the time where you can pick up 12mm, 1/2", 5/8" and sometimes 3/4" in birch, beech or maple. They sell to the Foundry and Tool & Die trade (millwrights/patternmakers). Don’t know what the shipping costs would be sorry to say.
